You have made your entry into the wholesale or retail market, but the hurdle you have stumbled upon is one faced by all wholesalers, that is, finding wholesale plus size clothing. One of the trickiest areas in wholesale is that of plus size clothing. You may get the style right but not the dimensions, or you may have trouble finding a good price , there are many websites that advertise that they are wholesalers but really they are not real wholesalers they are just another middle man. Most real plus size wholesalers have a MOQ (minimum order quantity) that means they have a minimum number of peices that you must purchase before they consider your order. Some wholesalers it is 20 some 50 some 100 and some require you to buy thousands of plus size clothing pieces.
Here are some links to wholeslaers that offer plus size wholesale clothing.
And alibaba.com is also a great community for plus size wholesale as well as all wholesale markets if you are interested in handbags or shoes etc. they connect the community to thousands of wholesalers and its free to join , I would defintely consider sighning up to Alibaba if you are serious about finding real wholesalers.